Update edit form for StockItem
Update edit form for StockItem

- Disallow direct quantity editing (must perform stocktake)
- Add notes field to allow editing

SchrodingersGat/InvenTree,inventree/InvenTree,inventree/InvenTree,SchrodingersGat/InvenTree,SchrodingersGat/InvenTree,inventree/InvenTree,SchrodingersGat/InvenTree,inventree/InvenTree